1. Technical Field
The present invention pertains to the field of accessories for automotive vehicles. More particularly, the present invention pertains to a towbar system for towing a disabled vehicle.
2. Discussion of related art
Ordinarily, in order to tow a disabled vehicle, a tow truck is used, having specialized equipment for raising one end of the vehicle off the ground and holding onto the raised end while towing the vehicle.
In some situations, and in particular in case of military vehicles on patrol or in battle, a tow truck cannot be used. Such vehicles, however, often include on their back end a so-called pintle hitch (i.e. a type of trailer hitch) to which a towbar can be attached for flat-towing (all four wheels on the ground) another (disabled) vehicle having D-rings or other means for attaching the towbar.
In case of the U.S. Army HMMWV (High Mobility Multi-purpose Wheeled Vehicle), a towbar is sometimes used including a heavy-gauge eyelet at one end—the tow-vehicle end—for attaching to a pintle hitch on the rear of the towing HMMWV, and two arms pivotally attached at the tow-vehicle end so as to allow adjusting the distance between the ends that attach to the front of the vehicle to be towed. When the towed and towing vehicle are hooked together by the towbar, the towbar can swivel around the Pintle hitch on the back of the towing vehicle.
A problem with the towbar that is sometimes used is that there is limited adjustibility to accommodate the typical situation where the vehicle to be towed is not substantially lined up with the towing vehicle. The two arms of the towbar are fixed in length, and the pintle hitch and the two points of attachment must therefore form an isosocles triangle (two sides equal in length) for the towbar to be hooked up. Thus, there is sometimes quite a bit of maneuvering of the towing vehicle before the hookup can be made. In battle, such maneuvering is often impossible.
In addition, once hooked up, if the towing vehicle brakes or stops when not perfectly aligned with the towed vehicle, then the towbar swivels about the pintle hitch and ends up getting cocked at sometimes a large angle. For example, if the towing vehicle is turning to the left so that the front wheels of the towed vehicle are also turned left, and the towing vehicle then brakes to a stop, then the towed vehicle will tend to continue forward with the wheels turned to the left, with the result that the towed vehicle will end up quite close to the towing vehicle, with the towbar swiveled sometimes to its extreme limit. This puts high stresses on the equipment of the towbar and the towed vehicle. And driving out of such a cocked configuration is sometimes difficult because the front wheels of the towed vehicle are often not suitably aimed to continue following the towing vehicle.
What is needed is a towbar that is easier to hook up, and that does not cock when the towing vehicle brakes to slow or stop.